A number of patents and publications are cited herein in order to more fully describe and disclose the invention and the state of the art to which the invention pertains. Each of these references is incorporated herein by reference in its entirety into the present disclosure, to the same extent as if each individual reference was specifically and individually indicated to be incorporated by reference.
Throughout this specification, including the claims which follow, unless the context requires otherwise, the word “comprise,” and variations such as “comprises” and “comprising,” will be understood to imply the inclusion of a stated integer or step or group of integers or steps but not the exclusion of any other integer or step or group of integers or steps.
As used herein, “a,” “an” and “the” include singular and plural referents unless the context clearly dictates otherwise. Thus, for example, reference to “an active agent” or “a pharmacologically active agent” includes a single active agent as well a two or more different active agents in combination, reference to “a carrier” includes mixtures of two or more carriers as well as a single carrier, and the like.
Ranges are often expressed herein as from “about” one particular value, and/or to “about” another particular value. When such a range is expressed, another embodiment includes from the one particular value and/or to the other particular value. Similarly, when values are expressed as approximations, by the use of the antecedent “about,” it will be understood that the particular value forms another embodiment.
Multiple Myeloma
Multiple myeloma is a disseminated malignancy of plasma cells that affects approximately 14,600 new patients each year in the United States. The etiology of this rare blood disease, affecting mainly the middle-aged to elderly population, is largely unknown although genetic predisposition and environmental factors have been implicated. From onset, malignant plasma cells arising from clonal expansion accumulate in the bone marrow, producing abnormally high levels of immunoglobulins. Multiple myeloma is difficult to diagnose early because there may be no symptoms in early stage. Bone pain especially secondary to compression fractures of the ribs or vertebrae is the most common symptom.
Dexamethasone is a commonly used regimen for first-line treatment of this disease. More recently, combinations of vincristine, doxorubicin, and dexamethasone (VAD) have been used to treat multiple myeloma. However, these are not effective long-term treatments. Dexamethasone treatment has a response rate of approximately 25-35%.
In many patients, high-dose chemotherapy supported by autologous stem cell transplantation (ASCT) may prolong event-free survival if the procedure is performed within 12 months of initial diagnosis. However almost all patients receiving high-dose chemotherapy and an autologous peripheral stem cell transplant will ultimately relapse.
Lymphoma
Despite years of research into the development of new methods of treatment, cancers of the lymphatic system, or lymphomas, remain quite common. For example, more than 60,000 people in the United States are diagnosed with lymphoma each year, including more than 55,000 cases of non-Hodgkin's Lymphoma (NHL), and these numbers are constantly increasing. In addition, the prognosis for those affected by these diseases is often poor, as the survival rates for lymphoma patients remain low. Clearly, new methods for treating these diseases are needed.
While traditional treatments for lymphoma typically depend on the type of lymphoma as well as the medical history of the patient, first-line treatment for many lymphomas typically includes chemotherapy. Such chemotherapy will often entail the administration of a “cocktail” of compounds, e.g., the formulation CHOP, which includes cyclophosphamide, doxorubicin, vincristine, and prednisone. In addition, certain first-line cancer treatments also include other forms of cancer therapy, such as radiation therapy.
In many cases, patients respond initially to such first-line treatments, but subsequently suffer a relapse, i.e., a tumor reappears or resumes growing. Following one such relapse, patients are often treated with further chemotherapy, e.g., with CHOP or with other formulations, or, in some cases, the patients are treated with other procedures such as bone marrow transplantation. Again, in many cases, patients initially respond to such additional treatments, but subsequently suffer another relapse. In general, the more relapses a patient suffers, the less agreement there is in the art concerning optimal subsequent treatment. In other cases, a patient fails to respond at all to a treatment, even initially, and is thus said to have a refractory cancer. In such cases as well, little agreement exists in the art regarding optimal subsequent treatment.
Leukemia
Leukemia is a malignant cancer of the bone marrow and blood. It is characterized by the uncontrolled growth of blood cells. The common types of leukemia are divided into four categories: acute or chronic myelogenous, involving the myeloid elements of the bone marrow (white cells, red cells, megakaryocytes) and acute or chronic lymphocytic, involving the cells of the lymphoid lineage.
Acute leukemia is a rapidly progressing disease that results in the massive accumulation of immature, functionless cells (blasts) in the marrow and blood. The marrow often can no longer produce enough normal red and white blood cells and platelets. Anemia, a deficiency of red cells, develops in virtually all leukemia patients. The lack of normal white cells impairs the body's ability to fight infections. A shortage of platelets results in bruising and easy bleeding. In contrast, chronic leukemia progresses more slowly and leads to unregulated proliferation and hence marked overexpansion of a spectrum of mature (differentiated) cells. In general, acute leukemia, unlike the chronic form, is potentially curable by elimination of the neoplastic clone.
It is estimated that there will be 28,700 new cases of leukemia in the United States this year; about equal proportions are acute leukemia and chronic types. Most cases occur in older adults. In fact, more than half of all cases of leukemia occur in persons over 60. The most common types of leukemia in adults are acute myelogenous leukemia (AML), with an estimated 9,400 new cases annually, chronic lymphocytic leukemia (CLL), with some 7,300 new cases this year, and chronic myeloid leukemia (CML). The most common type of leukemia in children is acute lymphocytic leukemia (ALL).
Standard treatment for leukemia usually involves chemotherapy and/or bone marrow transplantation and/or radiation therapy.
Chemotherapy in leukemia usually involves a combination of two or more anti-cancer drugs. Approximately 40 different drugs are now being used in the treatment of leukemia. Some common combinations include cytarabine with either doxorubicin or daunorubicin or mitroxantrone or thioguanine, mercaptopurine with methotrexate, mitroxantrone with etoposide, asparaginase with vincristine, daunorubicin and prednisone, cyclophosphamide with vincristine, cytarabine and prednisone, cyclophosphamide with vincristine and prednisone, daunorubicin with cytarabine and thioguanine and daunorubicin with vincristine and prednisone.
The two major types of bone marrow transplants are autologous (uses the patient's own marrow) and allogeneic (uses marrow from a compatible donor).
Radiation therapy, which involves the use of high-energy rays, is usually given before bone marrow transplantation to kill all leukemic cells.
Treatment of leukemia is very complex. Tremendous clinical variability among remissions is also observed in leukemic patients, even those that occur after one course of therapy. Patients who are resistant to therapy have very short survival times, regardless of when the resistance occurs. Despite improvements in outcome with current treatment programs, the need to discover novel agents for the treatment of all types of leukemia continues.
Thus, there is an urgent need for improved therapies for the treatment of multiple myeloma. Specifically, there is a need to discover effective single and combination therapies that will improve response rates and/or reduce the relapse rates in the treatment of multiple myeloma, both as first-line treatments and for the treatment of relapsed subjects.